Recent advances in livestock manure biochar Development in Korea: A review.

Distribution, assessment, and sources of nutrients in river water in the headwaters of the Shule River Basin, Northeastern Qinghai-Tibet Plateau.

Closing the loop in agriculture: life cycle assessment from manure to hydrogen and biofertilizer.

Dustfall source-apportionment and source-oriented health risk assessment using unsupervised machine learning, PMF, and HYSPLIT: Insights from a hotspot area in Xinjiang, China.

Evaluating aeration rate modulation to restructure denitrifier communities for nitrous oxide mitigation in cattle manure composting using a novel integrated analytical framework.

Breaking the cycle of resistance: Hyperthermophilic composting establishes a multi-layered defense against ARG dissemination.

ABSTRACT Excessive application of nitrogen (N) fertilizer has acidified soils to pH levels below the optimum, posing a threat to tea plant cultivation. Organic livestock manure rich in alkaline substances can counteract the H+ produced by soil nitrification of N fertilizer. However, how ameliorating acidification using livestock manure affects nitrification and greenhouse gas nitrous oxide (N2O) emissions in tea-planted soils remains unclear. Here, by adding four types of manure (cow, sheep, chicken, and pig) at rates of 0, 100, and 200 mg N kg−1 into a tea-planted soil, we showed that all manure additions alleviated soil acidification and increased net N mineralization and nitrification significantly, with the increases becoming more pronounced with increasing rate. While soil cumulative N2O emissions were enhanced significantly by sheep, chicken, and pig manure and reduced significantly by cow manure at the high rate, with opposite trends at the low rate. Net nitrification and cumulative N2O emissions were significantly and negatively correlated with carbon (C)/N of added manure at both rates and at the high rate alone, respectively. Our findings highlight the importance of selecting the appropriate livestock manure (i.e. high C/N) to alleviate soil acidification while minimizing nitrification and N2O emissions.

This study investigated the impact of urbanization on use of soil amendment by rice farmers in three villages along a rural–urban continuum in Northeast Thailand. It shows how urbanization influences their use of types and quantities of soil amendments. Data were collected by interviewing 150 farmers, focusing on types, quantities, sources, costs, and perceived effects of nine different amendments, including rice straw, chemical fertilizers, manures, and green manure. Results revealed significant declines in organic amendment use as villages become more urbanized, with rural farmers employing more diverse and greater quantities of organic amendments while periurban and urban farmers predominantly rely on chemical fertilizers. Quantitative analysis shows that livestock manure use diminishes sharply from over 80% of farmers in rural villages to around 30% in more urbanized communities, reflecting reduced livestock numbers. Discriminant analysis compared the three villages in terms of three dependent variables. (area of paddy fields, quantities of chemical fertilizer and organic amendments applied) showed clearly that all the group means were significantly different. Analysis of quantities of chemical fertilizer and organic amendments applied by individual farmers in all three villages revealed that farmers applying higher amounts of organic matter tended to use less chemical fertilizer. Constraints, including limited supplies, high costs, and labor shortages, inhibited organic amendment application among urbanized farmers. These shifts pose a serious threat to long-term soil quality. The findings underscore the urgent need for policy interventions to promote sustainable organic soil management practices in urbanizing communities to improve soil health and food security.

Integrated crop grazing systems can improve farm profitability due to enterprise complementarity. Utilizing the supply of N from legumes, livestock manure, and plant residues will result in improving grain yield and quality. A long-term 12-year integrated systems study evaluated continuous spring wheat (HRSW-CTRL) with spring wheat (HRSW-ROT) grown in a five-crop rotation: (1) spring wheat, (2) seven-species cover crop, (3) forage corn, (4) field pea/forage barley mix, and (5) sunflower. Yearling beef cattle steers grazed the field pea/forage barley mix, unharvested corn, and a seven-species cover crop. Spring wheat was marketed as a cash crop. Contrary to expectations, HRSW-ROT did not significantly increase grain yield or improve quality over HRSW-CTRL. Improved soil fertility was observed in the HRSW-ROT plots throughout the study relative to SOM, N, P, and K. However, the rotation with grazing management significantly reduced input costs but resulted in negligible gross and net returns over the 12-year period. Year-to-year weather variability was the cause of the differences between the two production management methods.

Piggery farming is the largest source of livestock manure in South Korea, yet greenhouse gas (GHG) data from piggery wastewater treatment systems remain limited. This study quantified methane (CH4) and nitrous oxide (N2O) fluxes from a full-scale treatment facility to develop stage-, seasonal-, and diurnal-specific emission factors. Continuous laser-based monitoring using a PVC air-pool chamber was applied across raw wastewater storage, an anoxic nitrogen-conversion reactor, and strongly aerated nitrification units. Mean CH4 fluxes ranged from 1.1 to 15.6 mg s−1 m−2 peaking in summer, while N2O fluxes ranged from 0.01 to 17,971 mg s−1 m−2, with maxima in fall. Emissions were dominated by two functional zones: aerated basins where vigorous mixing enhanced CH4 stripping, and an upstream anoxic reactor where oxygen instability and nitrite accumulation produced extreme N2O peaks. Derived emission factors were 0.11 kg CH4 head−1 yr−1 and 45.2 kg N2O head−1 yr−1, equivalent to 3.1 and 12,300 kg CO2-eq head−1 yr−1. CH4 variability was controlled mainly by treatment stage and temperature, whereas N2O was governed by internal redox conditions. These results refine emission factors for inventories and underscore the need for improved aeration stability and denitrification control to reduce GHG emissions from piggery wastewater systems.

Expansion of intensive livestock production has led to huge amounts of livestock manure, which is a great environmental threat if not well managed. Yet, management of livestock manure in dryland and its influence on dryland agrozones remains scarcely understood. A 90-day composting trials were established to assess the effects of different composting strategies on manure quality and its effect on physicochemical characteristics of arid and semi-arid (ASAL) soils. A plot trial was laid in a randomized complete block design with the following treatments: i) Control (T1), ii) 20 t ha-1 of cattle manure from open compost pit (T2), iii) 10 t ha-1 of goat manure ash added compost pit (T3), iv) 20 t ha-1 of cattle manure from covered compost pit (T4), v) 10 t ha-1 goat manure from open compost pit (T5), vi) 10 t ha-1 of goat manure from covered pit (T6), and vii) 20 t ha-1 of cattle manure ash added compost pit (T7). Manure quality from the composting pits differed significantly. Covered pits at 50cm depth recorded the highest Nitrate- N levels (188.0ppm), followed by open pits at 100cm (148.0ppm). Goat manure stored in covered pits had significantly lower subsoil nitrate (0.13 ± 0.14) compared with cattle manure in open or covered pits (T2 and T4; 0.47 ± 0.15 and 0.47 ± 0.03, respectively). Similarly, there was significant variations on soils collected from the plot trials. Soil moisture content improved significantly from 17.08% in T1 to 23.05% in covered pits. The lowest soil bulk density was recorded under plots receiving compost from the covered pits (1.02g/cm3). Moreover, nitrate-N at a depth of 10-20cm (p = 0.01) showed a significant treatment effect. Covered pits improved manure quality and soil physicochemical characteristics hence, could be a sustainable management approach that enhancese soil fertility and improving agricultural productivity in ASAL soils.

Veterinary drugs are widely present in animal manure and manure-based fertilizers, making their safety for use as soil amendments still ambiguous. This study investigated the concentrations of 17 typical veterinary drugs in animal manure and manure-based fertilizers from Shandong Province using solid-phase extraction coupled with high-performance liquid chromatography–tandem mass spectrometry and assessed their environmental risks to soil organisms based on risk quotient values. The established method demonstrated robust performance, with drug recovery rates ranging from 72.9% to 109%. Tetracyclines were identified as the most prevalent contaminants, with mean concentrations of 1522 μg/kg in animal manure and 144 μg/kg in manure-based fertilizers. Drug concentrations in manure-based fertilizers were generally lower than those in animal manure. Livestock manure contained higher drug concentrations compared to poultry manure. Influenced by farming practices, drug concentrations were higher in beef cattle manure than in dairy cattle manure, and higher in broiler manure than in layer manure. Manure-based fertilizers primarily derived their drug content from chicken, cattle, and sheep manure. Tetracyclines in swine and sheep manure posed high risks to soil organisms, while those in beef cattle manure and dairy cattle manure posed medium risks. In contrast, most drugs in manure-based fertilizers exhibited low risks. Comprehensive analysis of both concentration levels and ecological risks indicates that manure-based fertilizers represent a more feasible option for soil amendment. This study provides a theoretical foundation for better understanding the feasibility of applying animal manure and manure-based fertilizers to agricultural land.

Livestock manure is a major source of environmental pollution and greenhouse gas emissions if improperly managed. Aerobic composting represents a sustainable approach to manure recycling that can stabilize organic matter, mitigate carbon loss, and recover nutrients for agricultural use. In this study, sheep manure was mixed with sawdust to optimize the carbon-to-nitrogen (C/N) ratio and enhance aeration, and the mixture was subjected to aerobic composting with a cellulose-degrading microbial inoculant. To rigorously evaluate the biological effects, a control treated with sterilized inoculant was included to eliminate nutrient inputs from the carrier matrix. The inoculant significantly improved composting performance by extending the thermophilic phase by five days and reducing the C/N ratio to 19.8 on day 32, thereby shortening the composting cycle. Moreover, microbial inoculation enhanced nutrient retention, resulting in a 20.14% increase in total nutrient content, while the germination index (GI) reached 89.75%, indicating high compost maturity and reduced phytotoxicity. Microbial community analysis revealed that cellulose-degrading inoculants significantly altered microbial richness and diversity and accelerated community succession. Redundancy analysis (RDA) and hierarchical partitioning analysis showed that total organic carbon (TOC) and GI were the main environmental drivers of bacterial community dynamics, whereas pH and GI primarily regulated fungal community succession. These findings suggest a strong link between compost maturity and microbial community restructuring. This study demonstrates that cellulose-degrading microbial inoculation accelerates the composting of sheep manure, enhances organic matter degradation, and improves fertilizer efficiency while reducing the phytotoxicity of the final product.

The community service program by the KKN Tematik Team of Universitas Halu Oleo was carried out in Kondoano Village, Mowila District, South Konawe Regency. The aim of this activity was to enhance the knowledge and skills of farmers in utilizing Bali cattle waste through the application of biogas technology as a waste processing solution and alternative energy source. The implementation method began with a survey of the area to identify issues and potential, followed by technical guidance on biogas processing and activity evaluation. As a result, farmers gained knowledge and practical skills in converting livestock manure into biogas, which reduces environmental pollution and supports household energy needs. This activity involved the KKN Tematik team from the Faculty of Animal Husbandry, Universitas Halu Oleo, KKN students, and local farmers. This program successfully empowered the community to manage livestock waste independently into valuable and sustainable resources.

ABSTRACT Soil amendments and fertilizer products developed from municipal or agricultural waste streams, such as biosolids or livestock manure, are crucial to foster circular nutrient economies and reduce agricultural production costs, as well as to mitigate environmental impacts compared to traditional inorganic fertilizers. However, innovative technologies are required to develop municipal wastewater solids‐based fertilizers that are safe and effective for environmental application while reducing production costs and energy consumption compared to current technologies. A greenhouse pot experiment was conducted to assess the effects of novel municipal wastewater solids‐based products in the early stages of technological development at bench scale on plant growth and soil properties. Electrochemically‐treated waste activated sludge (EWAS), untreated waste activated sludge (WAS), a commercially available fertilizer produced from municipal wastewater solids (Milorganite), or a commercially available inorganic fertilizer (Greenview) was applied to pots containing wheat ( Triticum aestivum ) grown in field‐collected agricultural soil. Soil pH was higher with EWAS and Milorganite at the end of the 80‐day growth period, while Greenview‐treated soil had higher EC. Extractable soil P was 30% higher, while exchangeable soil Na was twice as high with EWAS as in unamended control soils. Wheat biomass was also significantly greater with EWAS compared to unamended controls and was comparable to the commercial fertilizers. This study demonstrates the potential efficacy of electrochemically‐treated wastewater solids as an amendment in field‐collected soil and highlights the need for further technological development of novel electrochemical processes designed to extract excess nutrients and deactivate pathogens in wastewater solids to create economically viable products while consuming less energy than conventional treatment methods.

Pig manure often creates environmental pollution and social issues for small-scale farmers. This community service activity empowers pig farmers to utilize manure for biogas production as an alternative energy source and as a bioslurry for organic fertilization. We applied socialization and assistance, and constructed dome-type biogas digesters using locally available materials. We analyzed the potential of biogas based on the number of livestock and daily manure production, then connected this to household cooking energy needs. The results indicate that farmers can use the resulting biogas as a substitute for LPG for cooking, reducing their dependence on LPG. Additionally, bioslurry can serve as organic fertilizer, supporting agriculture and household gardens. Socio-economically, this activity enables energy cost savings, improves environmental conditions around pens, and fosters greater social acceptance of pig farming. Overall, transforming livestock manure into biogas and bioslurry provides a sustainable empowerment model for farmers, which communities can replicate.

Robust, national-scale quantification of soil organic carbon (SOC) dynamics in China’s paddy fields has been hindered by widely divergent estimates and a lack of comprehensive driver attribution. To address this, we developed a new empirical model from a comprehensive database of 746 long-term field observations (125 sites) to identify predominant drivers and quantify national-scale SOC stock dynamics from 1980 to 2018. The model explained 43% of the variance in topsoil SOC change. Organic matter input was the dominant driver (21.83% variance), with livestock manure demonstrating the highest C sequestration efficiency, followed by green manure and straw. Soil pH, latitude (as a climate proxy), and initial SOC content were also critical controllers. We estimate that China’s paddy topsoils (0–20 cm) acted as a significant C sink from 1980 to 2018, accumulating 242.51 ± 85.80 Tg C (an average rate of 6.65 Tg C yr−1), bringing the 2018 national stock to 1220.48 ± 85.80 Tg C. Spatially, sequestration was highest in central (e.g., Hunan) and northeastern (e.g., Heilongjiang) China, while Chongqing experienced a net SOC loss. Crucially, our study provides a new long-term benchmark that reconciles previous, higher estimates from shorter timeframes, empirically demonstrating that sequestration rates are non-linear and diminish over time. These findings confirm that the C sequestration potential of paddy soils, while substantial, is finite and requires spatially targeted management of organic inputs and soil pH to maintain.

Sustainable nutrient management remains a critical challenge for agri-food systems worldwide, particularly in resource-constrained island regions. Excessive nitrogen (N) and phosphorus (P) losses, driven by reliance on imported fertilizers, feed, and inefficient waste management, contribute to eutrophication, greenhouse gas emissions, and soil degradation. These environmental burdens undermine the resilience and sustainability of food systems. This study employed material flow analysis (MFA) to evaluate nutrient flows and losses in Taiwan, a densely populated island that is highly dependent on external nutrient inputs. Results indicate annual inflows of 358.6 kt N and 118.3 kt P, of which 84% of N and 48% of P are lost, primarily through domestic and industrial wastewater discharge and manure mismanagement. Scenario-based assessments demonstrate that enhanced biowaste recycling, including livestock manure, food waste, and wastewater, could reduce fertilizer imports and mitigate greenhouse gas emissions by up to 98,299 t CO2 eq annually. While some progress has been made in municipal wastewater valorization, broader implementation of nutrient recovery strategies remains limited. The findings underscore the need for integrated policy frameworks and cross-sectoral collaboration to enhance nutrient circularity, reduce environmental pressures, and support cleaner food production in island settings. This study provides a comprehensive systems-level assessment of nutrient use inefficiencies and recovery opportunities, offering actionable insights for decision-makers and environmental planners. The approach and findings are relevant for developing science-based policies to improve sustainability in vulnerable agri-food systems globally.

Groundwater nitrate contamination is largely attributed to fertilizer and intensive livestock manure inputs in agricultural systems. California's Salinas Valley is an area where regional policy is aimed at reducing nitrate leaching. Nonlegume winter cover crops can help decrease nitrate leaching by scavenging residual soil nitrogen (N) during winter fallow periods following the cropping season. However, the ability of fall-incorporated cover crops to decrease nitrate leaching and recycle N to subsequent cash crops is unknown. We conducted a 112-day laboratory soil incubation experiment using Merced rye (Secale cereale) cover crop shoot biomass, with four carbon-to-nitrogen (C/N) ratios (10, 14, 19, and 30), at three temperatures (10°C, 15°C, and 20°C). Destructive soil sampling was done at six intervals during the incubation to measure plant-available nitrogen. Rye biomass with the lowest C/N ratio (10) had the highest average nitrogen mineralization (Nmin) rate (56%) at the warmest temperature (20°C). Conversely, biomass with the highest C/N (30) showed net nitrogen immobilization at 10°C and 15°C during the incubation, transitioning to net mineralization only at 20°C. We found a linear correlation between soil temperature and nitrogen mineralization (at Day 112) for higher C/N ratios. Furthermore, doubling the soil mineral nitrogen content had a negligible impact on the percent mineralization of the C/N 30 residue. These results provide useful information to help farmers and policymakers understand mineralization dynamics from fall-, winter-, or spring-terminated cereal cover crops.

The appropriate use of external additives can reduce greenhouse gas emissions from livestock manure composting and improve compost quality. Using basalt and diorite tailings as subjects, this study investigates the effects of these tailings residues on compost quality, carbon transformation, and retention, as well as CO2 and CH4 emissions during the composting process. The results showed that, similar to the control compost, the compost products with 10% basalt and diorite tailings residue treatments met the NY/T 525-2021 organic fertilizer standards in terms of heap temperature, pH, organic matter, and total nutrient content. This addition also reduced moisture, improved the seed germination index, and supported organic matter and total nutrient （N, P, and K） accumulation. Notably, in the basalt treatment, organic matter loss rate decreased from 15.6% to 2.6% compared to that in the control, and total nutrient accumulation increased from 101% to 114.6%. The addition of basalt tailings aided in carbon stabilization within pig manure compost. Compared to that in the control treatment, the total organic carbon loss rate in the basalt tailings residue treatment decreased from 15.6% to 2.9%. Non-soluble organic carbon accumulated, CO2 and CH4 cumulative emissions from composting were reduced by 23.5% and 24.4%, respectively, and the humification coefficient of the compost product increased by 56.3%. Nuclear magnetic resonance carbon spectroscopy further indicated that the addition of tailings residues promoted the decomposition of lignocellulosic components in the pig manure heap, facilitating their transformation into more stable aromatic carbon. The study provides important theoretical and technical support for the efficient, low-carbon, and synergistic recycling of tailings and livestock manure.